Inverse Design of Multi-Port Power Splitter with Arbitrary Ratio Based on Shape Optimization

Area of Science:

• Photonics and Optical Engineering
• Materials Science for Integrated Circuits
• Nanophotonics

Background:

• Arbitrary ratio power splitters (APSs) are key for flexible photonic integrated circuits (PICs) on silicon-on-insulator (SOI).
• Existing APS designs typically offer only two output channels, limiting their application scope.
• Advanced power management in PICs requires multi-channel splitting capabilities.

Purpose of the Study:

• To develop a novel multiport arbitrary ratio power splitter (MAPS) using shape optimization.
• To achieve arbitrary power distribution across three output channels in a compact footprint.
• To validate the MAPS designs through simulation and experimental measurements.

Main Methods:

• A shape optimization method was employed to design the MAPS.
• The MAPS was designed for a compact footprint of 6 µm × 2.7 µm.
• Simulations and experimental measurements were conducted to validate performance.

Main Results:

• Two MAPS designs with power ratios of 1:2:1 and 1:2:4 were successfully demonstrated.
• Designs achieved desired power distribution with excess losses (ELs) below 0.5 dB over a 1500-1600 nm bandwidth.
• Experimental validation showed ELs below 1.3 dB across a 1500-1565 nm bandwidth.

Conclusions:

• The shape optimization method enables the development of compact, three-channel MAPS for PICs.
• The demonstrated MAPS designs offer flexible and efficient power splitting capabilities.
• This work advances the functionality of SOI-based photonic integrated circuits.